1. Field of the Invention
The present invention relates generally to fiber optic interconnect devices and methods, and more particularly to single fiber transceivers for integration into electronic microcircuits.
2. Description of the Related Art
With advances in data communications, increased emphasis is being placed on using optical fibers to replace conventional electrical wires as a signal transmission medium. Unlike electrical wires, the use of optical fibers necessarily requires an interface device for coupling between the electronic device and the optical fiber. Because most state-of-the-art electronic devices require bi-directional transmission of data for proper operation, interface devices must be capable of both transmitting signals into an optical fiber and receiving signals from an optical fiber. Devices which are specifically designed for exchanging data in this manner are commonly known as optical transceivers. Accordingly, the use of optical fibers as a replacement for electrical wires is largely dependent on the advancements made in the design of transceiver devices and methods.
Two examples of commercially available transceivers are the FSD Transceiver manufactured by Amp Incorporated which is disclosed in the Amp Inc. Product Data Sheets, and the FDDI Optical Data Link manufactured by Sumitomo Electric Industries and disclosed in SEI News, Issue No. 92-14, dated September 1992. Although currently known transceivers, such as those mentioned above, are useful for their intended purposes, they severely limit the use of fiber optics in many applications.
One major drawback of currently known transceivers is their large packaging dimensions. This makes them ineffective for many small scale electronic applications, such as interconnecting electronic microcircuits. The inability to integrate transceiver packages and make them more compact is due to a number of design factors.
One such design factor is the thermal limitations of the transceiver package. Light sources such as diode lasers and LEDs (light emitting diodes) are heat generating devices. Therefore, the integration of these devices into microcircuit packages creates thermal management problems.
Another design limitation of currently known transceiver technology is the use of conventional pigtail coupling between the electronic device and the optical fiber. Along with the added space that this type of coupling requires, it often leads to significant signal power losses when transmitting light into an optical fiber. This is due mainly to the precise alignment necessary in interfacing the electronic device with the fiber. Furthermore, the risk of improper alignment leading to a complete loss of signal communication makes this method of coupling unreliable and impractical in many fiber optic applications. The use of conventional pigtailing also prevents optical fibers from being used for wavelength multiplexing operations, such as simultaneous communication between a number of transceivers interconnected on a single optical fiber.
Finally, currently known transceivers require two separate optical fibers for data communication; one for transmitting and one for receiving. U.S. Pat. No. 4,444,460, entitled "Optical Fiber Apparatus Including Substrate Ruggedized Optical Fibers," issuing to Stowe, discloses the use of a single optical fiber for allowing certain wavelengths of light to be diffracted into or out of an optical fiber. This patent, however, does not teach or suggest a device or method of integrating electronic devices with an optical fiber for optically communicating between the electronic device and the optical fiber. As such, Stowe does not explore the relationship of using a single optical fiber in optical transceiver devices.